Taking a stab at making home made hazelnut extract. Here's what I did:

Took two 8oz mason jars (boiled), and put 1 split and scraped vanilla bean in each. Then I took 16 oz of hazelnuts and split them into two parts. I baked for 9min at 350º. Then I removed them and let them cool for a minute. Then I de-husked them. For one of the piles (8oz) I grated the nuts on a cheese grater. Then I put both piles back in the oven for 9 more minutes. Took them out and put each pile into their separate mason jars with the vanilla bean. Poured vodka to the top. Sealed.

I just used a cheese grater and got each nut down to the point where I couldn't hold it anymore.

Unexpected: I couldn't actually fit all the grated nuts in the 8oz jar.

I did a similar thing this past Saturday. Cracked some roasted hazelnuts with my fist and put them in vodka. I only had about an ounce of nuts though. The hazelnuts are not yet coming through strongly. I'll be interested to hear how your experiment goes.